For the line art on the tunic, just use Heat n' Bond. It will save your life and you won't need to sew a thing. As for the armor, I used this famous Foam armor technique. http://entropyhouse.com/penwiper/costumes/helmsdeep.html

Personal Thoughts:

I designed this concept for Lady Thor. It was inspired by the silhouette of the modern Thor from the comics and the armor in the Marvel movies.